Abstract: A system and method for on-line shopping are disclosed. The system and method allow one or more entities to sponsor on-line shopping programs that are individually tailored for each sponsor and at the same time provide a high degree of security flexibility and user flexibility. A programs sponsor can assign each user of the program an amount of credit, such as a performance-based reward. The sponsor can also select a set of vendors from whom the user can make purchases with the credit. The sponsor can establish conversion rates between the assigned credit and the currency used by the vendors if the credit is assigned in a unit (such as points) different from the currency unit (such as dollars). The user can then use the credit to shop at any of the vendors' on-line store while being reminded of the available credit displayed in the currency unit.